Textbook Question
Electrostatic potential maps of acetic acid (CH3CO2H) and ethyl alcohol (CH3CH2OH) are shown. Identify the most acidic hydrogen in each, and tell which of the two is likely to be the stronger acid.
<IMAGE>
1
views
Ch.10 Acids and Bases
McMurry8th EditionFundamentals of General, Organic, and Biological ChemistryISBN: 9780134015187
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 Matter and Measurements27
- Ch.2 Atoms and the Periodic Table20
- Ch.3 Ionic Compounds8
- Ch.4 Molecular Compounds23
- Ch.5 Classification & Balancing of Chemical Reactions12
- Ch.6 Chemical Reactions: Mole and Mass Relationships28
- Ch.7 Chemical Reactions: Energy, Rate and Equilibrium64
- Ch.8 Gases, Liquids and Solids24
- Ch.9 Solutions52
- Ch.10 Acids and Bases25
- Ch.11 Nuclear Chemistry22
- Ch.12 Introduction to Organic Chemistry: Alkanes57
- Ch.13 Alkenes, Alkynes, and Aromatic Compounds47
- Ch.14 Some Compounds with Oxygen, Sulfur, or a Halogen50
- Ch.15 Aldehydes and Ketones45
- Ch.16 Amines42
- Ch.17 Carboxylic Acids and Their Derivatives57
- Ch.18 Amino Acids and Proteins82
- Ch.19 Enzymes and Vitamins63
- Ch.20 Carbohydrates44
- Ch.21 The Generation of Biochemical Energy65
- Ch.22 Carbohydrate Metabolism45
- Ch.23 Lipids42
- Ch.24 Lipid Metabolism33
- Ch.25 Protein and Amino Acid Metabolism24
- Ch.26 Nucleic Acids and Protein Synthesis45
McMurry8th EditionFundamentals of General, Organic, and Biological ChemistryISBN: 9780134015187Not the one you use?Change textbook
Chapter 10, Problem 9
From this electrostatic potential map of the amino acid alanine, identify the most acidic hydrogens in the molecule:
<IMAGE>![]()
Verified step by step guidance1
Examine the electrostatic potential map provided. The red regions indicate areas of high electron density, which are typically associated with acidic groups capable of donating protons (H⁺). Blue regions indicate areas of low electron density, which are less likely to donate protons.
Identify the functional groups in alanine. Alanine contains an amino group (-NH₂), a carboxylic acid group (-COOH), and a methyl group (-CH₃). The carboxylic acid group is typically the most acidic functional group in amino acids.
Focus on the hydrogens attached to the carboxylic acid group (-COOH). The hydrogen bonded to the oxygen in the hydroxyl (-OH) part of the carboxylic acid is the most acidic hydrogen in alanine.
Use the electrostatic potential map to confirm this observation. The red region around the oxygen atoms in the carboxylic acid group indicates high electron density, which stabilizes the negative charge formed when the hydrogen is donated as a proton.
Conclude that the most acidic hydrogen in alanine is the one attached to the oxygen atom in the hydroxyl (-OH) group of the carboxylic acid functional group.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Electrostatic Potential Map
An electrostatic potential map visually represents the distribution of electric potential around a molecule. Areas of high electron density appear in red, indicating regions of negative charge, while blue areas indicate positive charge. This map helps identify reactive sites, such as acidic hydrogens, by showing where protons are more likely to dissociate.
Recommended video:
Guided course
02:04
The Atom (Simplified) Example 2
Acidic Hydrogen
An acidic hydrogen is a hydrogen atom that can be easily released as a proton (H+) in a chemical reaction, typically found in functional groups like carboxylic acids. In the context of amino acids like alanine, the acidic hydrogen is often associated with the carboxyl group (-COOH), which has a tendency to donate protons, thus exhibiting acidic behavior.
Recommended video:
Guided course
1:22Hydrogenation Reactions Concept 1
Acid-Base Strength
Acid-base strength refers to the ability of a substance to donate protons (acids) or accept protons (bases). This strength is influenced by the stability of the resulting ions after dissociation. In amino acids, the presence of electronegative atoms and the molecular structure can affect the acidity of specific hydrogens, making some more likely to ionize than others.
Recommended video:
Guided course
00:50Acid and Base Strength Concept 3
Related Practice
Textbook Question
What happens when a strong acid such as HBr is dissolved in water?
1
views
Textbook Question
Show how ethylamine (C2H5NH2) reacts with hydrochloric acid to form an ethylammonium salt.
Textbook Question
Write a balanced equation for the proton transfer reaction between hydrofluoric acid (HF) and ammonia (NH3). Identify each conjugate acid-base pair, and rewrite the equilibrium arrows to indicate if the forward or reverse reaction is favored.
1
views